The present invention relates to an ionomer resin and a method for the preparation thereof and, more particularly, to an ionomer resin which is of a novel chemical structure and excels in mechanical strength, oxygen gas barrierring ability and an efficient method for the preparation thereof.
Heretofore, polyolefin resins have found use in wide applications due to a number of excellent properties, but have offered problems in connection with printability and dyeing properties because of chemical inertness. In one metnod proposed to solve these problems, olefins are copolymerized with polar vinyl monomers. In another method for that purpose, olefins are copolymerized with polar vinyl monomers, followed by crosslinking with metal ions (Japanese Patent Publication No. 39(1964)-6810). The resins obtained by the latter method in particular have been named the ionomer resins by R. W. Rees, et al and, since then, inomer resins of various structures have been proposed in the art. These ionomer resins are typically represented by ethylene-methacrylic acid copolymers obtained by the high-pressure process and crosslinked with Na.sup.+ or Zn.sup.++. However, they are still found to be unsatisfactory in terms of heat resistance, mechanical strength, oxygen gas barrierring ability and so on.